Learn from Attrition
There are some good pieces of advice in this HBR article that go beyond my own, simple view of attrition.
I believe there are simple and predictable reasons why colleagues leave jobs to pursue new opportunities. I believe we all quit jobs when one or more sides of what I call the "fulfillment triangle" are broken. We stay in roles and jobs when we "like" what we are doing, when we feel "safe" in the environment and when the "dollars" earned are acceptable. If any side is impaired, we are a flight risk. You can learn more about the fulfillment triangle in my book, Whiteboard Wisdom, and every HR department can easily incorporate an analysis of that triangle into every exit interview to gain greater insights and lower future unplanned attrition.
You can find my book here: https://amzn.to/2M3e3Gs